.\" $OpenBSD: SSL_CTX_set_min_proto_version.3,v 1.4 2020/05/12 20:12:44 tb Exp $
.\" full merge up to: OpenSSL 3edabd3c Sep 14 09:28:39 2017 +0200
.\"
.\" This file was written by Kurt Roeckx <kurt@roeckx.be> and
.\" Christian Heimes <christian@python.org>.
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.Dd $Mdocdate: May 12 2020 $
.Dt SSL_CTX_SET_MIN_PROTO_VERSION 3
.Os
.Sh NAME
.Nm SSL_CTX_set_min_proto_version ,
.Nm SSL_CTX_set_max_proto_version ,
.Nm SSL_CTX_get_min_proto_version ,
.Nm SSL_CTX_get_max_proto_version ,
.Nm SSL_set_min_proto_version ,
.Nm SSL_set_max_proto_version ,
.Nm SSL_get_min_proto_version ,
.Nm SSL_get_max_proto_version
.Nd get and set minimum and maximum supported protocol version
.Sh SYNOPSIS
.In openssl/ssl.h
.Ft int
.Fo SSL_CTX_set_min_proto_version
.Fa "SSL_CTX *ctx"
.Fa "uint16_t version"
.Fc
.Ft int
.Fo SSL_CTX_set_max_proto_version
.Fa "SSL_CTX *ctx"
.Fa "uint16_t version"
.Fc
.Ft int
.Fo SSL_CTX_get_min_proto_version
.Fa "SSL_CTX *ctx"
.Fc
.Ft int
.Fo SSL_CTX_get_max_proto_version
.Fa "SSL_CTX *ctx"
.Fc
.Ft int
.Fo SSL_set_min_proto_version
.Fa "SSL *ssl"
.Fa "uint16_t version"
.Fc
.Ft int
.Fo SSL_set_max_proto_version
.Fa "SSL *ssl"
.Fa "uint16_t version"
.Fc
.Ft int
.Fo SSL_get_min_proto_version
.Fa "SSL *ssl"
.Fc
.Ft int
.Fo SSL_get_max_proto_version
.Fa "SSL *ssl"
.Fc
.Sh DESCRIPTION
These functions get or set the minimum and maximum supported protocol
versions for
.Fa ctx
or
.Fa ssl .
This works in combination with the options set via
.Xr SSL_CTX_set_options 3
that also make it possible to disable specific protocol versions.
Use these functions instead of disabling specific protocol versions.
.Pp
Setting the minimum or maximum version to 0 will enable protocol
versions down to the lowest or up to the highest version supported
by the library, respectively.
.Pp
Currently supported versions are
.Sy TLS1_VERSION ,
.Sy TLS1_1_VERSION ,
and
.Sy TLS1_2_VERSION
for TLS and
.Sy DTLS1_VERSION
for DTLS.
.Pp
In other implementations, these functions may be implemented as macros.
.Sh RETURN VALUES
The setter functions return 1 on success or 0 on failure.
.Pp
The getter functions return the configured version or 0 if
.Fa ctx
or
.Fa ssl
has been configured to automatically use the lowest or highest
version supported by the library.
.Sh SEE ALSO
.Xr ssl 3 ,
.Xr SSL_CTX_new 3 ,
.Xr SSL_CTX_set_options 3
.Sh HISTORY
The setter functions first appeared in BoringSSL in December 2014,
with shorter names without the
.Sy proto_
part.
Two years later, OpenSSL included them in their 1.1.0 release,
gratuitously changing the names; Google shrugged and adopted
the longer names one month later.
They have been available since
.Ox 6.2 .
.Pp
The getter functions first appeared in OpenSSL 1.1.0g
and have been available since
.Ox 6.3 .
